Air cleaner



Feb. 19, 1935. 'w .w ow ER 1,991,758

AIR CLEANER Filed 1360.15, 1953 I Patented Feb. 19, 1935 UNITED STATESPATENT OFFICE AIR CLEANER Application December 15, 1933, Serial No.702,483

7 Claims. (01. 183-15) My present invention provides a simple andreliable air cleaner of high emciency adapted for use "in connectionwith internal combustion engines and capable of meeting all of therequirements of internal combustion engines 01' high power capacityhaving a small number of cylinders wherein the air is drawn to thecarburetor with pulsating actions that vary, to a considerable extent,the velocity of the air flow through the air cleaner. The presentinvention is shown as embodied in an air cleaner, some of the featuresof which are common to that illustrated in the drawings of my companionapplication, 8. N.

702,482, filed of date December 15, 1933.

My present invention is illustrated in the single view or drawing whichis an axial section taken through the complete air cleaner. The aircleaner, as shown, involves an outer casing or shell 5, preferably inthe form of an upright cylinder, the lower end or which is primarilyopen. An axial air intake tube 6 extends downward through the casing 5.A large or main ,oil we11 7, or cup-shaped form and closed at itsbottom, is telescoped onto the lower end or the easing 5 and closes thelower end of said casing. This oil well 7 is made readily detachable andis secured to the casing by suitable means such as upwardlyspring-pressed hook-b0lts'8 that work through lugs 9 on the exterior ofthe casing and engage out-turned lugs 10 on the exterior of the upperedge of said oil well.

At the upper end of the casing is an air chamber 11 that surrounds theupper portion oi. the air intake tube 6 and is provided with an airoutlet 12 adapted to be coupled to the carburetor of an internalcombustion engine. An oil distributing dust-intercepting screen A isplaced in the annular space between the casing and the intake tube andextends from the bottom or 40 1 chamber 11 down to a point near to butconsiderably above the lower end of the air intake tube.

This screen is preferably made from quite finely woven wire and may takevarious forms. For example, it may be such as that disclosed in theapplication of William H. Schulz, S. N. 616,885, filed June 14, 1932,and entitled "Air cleaner".

For the purpose of this case,.attention is simply called to the factthat the screen, as shown, is made up of annular woven wire members, the50 surfaces of which are inclined in such a way that the oil interceptedby the screen will run down over and form films of oil over the openingsof the screens and through which oil films, the air will be caused topass and, by the oilfilms, the 5 dust will be intercepted and returnedtov the oil well. At its extreme lower end, the air intake tube 6isprovided with an outstanding annular flange 13. The elements so farspecifically described are common to the structure illustrated in thecompanion application above identified. 5

As a highly important feature of the present invention, the oil well isprovided just below and immediately surrounding the lower end of the airtube with a secondary or minor oil receptacle in the nature of a closedbottom oil cup 41 shown 10 as formed by an annular collar 15, the loweredge of which is secured to the bottom of the oil well .7. The normal orstatic oil level 01' the oil well is at 11-1! and which level, it willbe noted, is well above the lower end of the air tube 6. The. 15cup-forming collar 15, it is important to note, extends somewhat abovethe plane or the flange 13, but well below the normal oil level.

Spaced concentrically from the cup-forming collar 15 and from the wallsof the oil well and 20 of the casing is an annular baiiie 16 which maybe supported in various diirerent ways, for example, by means of spacingstuds or lugs 1'! that connect the same to the cup-forming collar 15, sothat both of the said members 15 and 16 will 25 be removable with theoil well. This baille, it is important to note, terminates at its loweredge high above the bottom or the oil well 7 and extends above the upperedge of the collar 15 and terminates at its upper edge'approximately at30 the oil level yy. It will now be noted that the flange 13, on thelower end of the air tube 6, forms a restricted annular air passage 18between the same and the collar 15. r

Operation Normally, as stated, the oil level will be approximately atthe line 1/1I. Under the action of suction produced by the engine, amore or less rapid current of air will be drawn to the car- 40 buretor,through the air intake tube 6 into the chamber formed within the oil cup14. thence upward through the screensinto the air chamber 11 and outthrough the air discharge tube 12. Air discharged from the lower end ofthe air tube 6 willbe dashed against the oil in the oil cup 14 and theoil in said cup will be depressed to an extent depending on the velocityor the air and will be dashed into a spray or foam and carried upward bythe air through the openings in the 5 screen, to a greater or lessheight, depending on the force of the air. The oil displaced from thecup 14 and passed upward into the screen chamber will, under any normaldegree of air velocity. ultimately be intercepted by the screen elementsand will accumulate thereon and run downward over the declined surfacesthereof. That portion of the oil displaced from the cup 14, which runsover the outward declines of the screens, will accumulate and form ahead of oil in the lowerouter portion of the oil well, that are radiallyoutward of the annual baffle 16. Oil accumulating on'the inward declinesof the screen elements, will eventually reach an eddy space closelyadjacent the intake tube, which eddy space forms as a result of theflange 13, and will be free to run downward along the intake tube. Undercontinued operation with substantially constant air velocity the oillevel in the cup 14 will remain substantially constant, there beingunder these conditions substantially no flow of oil either into or outof the cup 14, and oil supply to air stream will be afforded from thefollowing noted sources, to wit: (a), from between the cup 14 and baffle16, as a result of suction produced by the rapid movement of air passedover the edge of-the cup 14, and the head of oil maintained outward ofthis point, (b), from the upper edge of the baffle 16 by oil from theannular head of oil overflowing the baflle 16, and (c), from downwardlyflowing oil in the eddy space adjacent the intake tube which overflowsthe edge of the flange 13. Substantially all of the oil supplied to theair stream from the sources (a), (b) and (c), noted, is whipped up bythe air at the point of highest air velocity and is returned to thescreen chamber, substantially the only return of oil from the screenchamber to the oil well being outward of the bafile 16. It will beobvious that under the conditions above noted, there will be a continualcirculation of oil downward between the bafile 16 and the wall of theoil well and upward between bafile 16 and cup 14.

It is important to maintain a high air velocity close to the point wherethe air makes its initial upward turn against the oil and passes betweenthe intake tube and the wall of cup 14 so that under normal operatingconditions, all of the oil delivered to the air stream at this pointwill be whipped up by the air and carried back into thescreen-containing chamber, which chamber might well be termed anexpansion chamber, since the air stream expands rapidly upon enteringthe same. This rapid and relatively great expansion of the air as itleaves the cup 14 and baflle 15, and enters the screen-containingexpansion chamber, causes oil delivered into the air stream at thispoint to be finely broken up or atomized so that it will pass upwardinto the screen elements in the nature of a fine mist. Flange 13 servesthe dual function of increasing air velocity at the point of itsdelivery to the screen or expansion chamber, and produces the eddy spaceadjacent the intake tube so as to permit return of oil to the highvelocity point of the air stream and said flange 13, is therefore, avery desirable and important element.

Most and all of the heavy particles of dust are thrown directly into andarrested by the oil in the cup when the air makes its upward turnagainst the surface of the oil in said cup, and the balance of said dustor foreign substance which will represent only the very light andhardest to arrest dust or foreign substance, will turn with the air andbe delivered to the screen-containing expansion chamber, where it willbe arrested either by oil suspended in the air or on the screens andeventually will be returned to and deposited in the oil well. Oilflowing downward over the screen element forms films over the openingstherein through which air must pass, so that all the dust carried in theexpansion chamber is arrested therein and usually before having traveledbut a short distance through the expansion chamber. The vertical extentof the screen-containing chamber is such that oil will not be carried upthrough all of the screens or screen elements even by intense pulsationsproduced by large two-cylinder internal combustion engines. Of course,also the altitude to which the oil will be carried will depend on theengine speed regardless of the number of cylinders and the variation inthe intensity of the pulsations.

When the speed of the engine and hence the velocity of the airdecreases, there will be an overflow of at least part of the oil fromthe oil Well into the oil cup, and when the engine is inoperative, theoil will reach a static condition and will then overflow into andcompletely fill the oil cup and the interior of the baffle 16, as theoil reaches its normal or static level.

The arrangement has, in practice, been found highly eflicient for thepurposes indicated. It also has the advantage of affording acomparatively short air cleaner, due to the fact that the oil cup andoil well have a common bottom which shortens up the vertical extent ordimension of the oil well and hence of the entire air cleaner.

What I claim is:

1. An air cleaner comprising a casing having an oil well at its bottomand an air outlet at its upper portion, a closed bottomed oil cup insaid well ofless diameter and vertical extension than said well, an airtube extended 'axially downward through said casing with its lower endarranged to deliver air into said oil cup, and an annular baflie spacedaround said oil cup with its upper edge extended above the upper edge ofsaid cup, the annular space between said baflle and cup being open forfree communication with the bottom of said well. I r

2. An air cleaner comprising a casing having an oil well at its bottomand an air outlet at its upper portion, a closed bottomed oil cup insaidwell of less diameter and vertical extension than said well, an air tubeextended axially downward through said casing with its lower endarranged to deliver air into said oil cup, and an annular bafile spacedaround said oil cup with its upper edge extended above the upper edge ofsaid cup, the annular space between said baffle and cup. being open forfree communication with the bottom of said well, the upper edge of saidoil cup being above the lower end of said air tube and the upper edge ofsaid bafile being approximately at a normal or static oil level that iswell above the upper edge of said cup and above the lower end of saidair tube.

3. An air cleaner comprising a casing having an oil well at itsbottomand an air outlet at itsupper portion, an oil cup in said well of lessdiameter and vertical extension than said well, an air tube extendedaxially downward through said casing with its lower end arranged todeliver air into said oil cup, and an annular bafiie spaced around saidoil cup with its upper edge between said baffle and cup being open forfree communication with the bottom of said well, said air tube at itslower end having an outstanding annular flange that forms a restrictedannular air passage between the same and the well of said oil cup.

4. An air cleaner comprising a casing having an oil well at its bottomand an air outlet at its upper portion. an oil cup in said well of lessdiameter and vertical extension than said well, an air tube extendedaxially downward through said casing with its lower end arranged todeliver air into said oil cup, and an annular baffle spaced around saidoil cup with its upper edge extended above the upper edge of said cup,the annular space between said baffie and cup being open for freecommunication with the bottom of said well, the upper edge of said oilcup being above the lower end of said air tube and the-upper edge ofsaid bafile being approximately at a normal or static oil level that iswell above the upper edge of said cup and above the lower end of saidair tube, said air tube at its lower end having an outstanding annularflange that forms a restricted annular air passage between th same andthe well of said oil cup.

5. The structure defined in claim 2 in which said oil cup and oil wellhave a common bottom and are together detachable from said casing.

6. An air cleaner comprising a casing having a closed bottomed oil wellin its bottom and an air inlet at its upper portion, an oil cup in saidwell of less diameter than said well, an air intake tube extendingaxially downwardly through the casing with its lower end extending belowthe top of and arranged to deliver air into said oilcup, the oil in saidwell having a normal static level above the oil cup and the delivery endof the intake tube, whereby under the action of air passed through thecleaner, oil will be. displaced from the cup and build up a head of oiloutward of the oil cup which will,.under continued flow of air, overflowthe edges of the cup and maintain the air stream supply with oil.

7. The structure defined in claim 1 in which the oil well is detachablyapplied to the lower 1 end of the casing and in which the oil cup andannular baffle are carried by and. detachable with said oil well.

WILF'RED W; LOWTHER.

